鞭毛藻和硅藻是沿海水域中非常普遍和生态重要的浮游植物,极大地促进了海洋生态系统的初级生产力。尽管它们的组成和多样性在公海中得到了广泛的阐明,在长期富营养化的沿海水域中,它们的相互作用模式和社区集会仍然知之甚少。这项研究旨在通过在半封闭海湾中进行18SrRNA基因扩增子测序来阐明鞭毛藻和硅藻的季节性演替模式。结果表明,鞭毛藻和硅藻群落具有明显的季节性演替模式,这主要与温度有关。此外,全年最普遍的物种是Heterocapsarotundata和Skeletonemacostatum。此外,鞭毛藻和硅藻群落的组装主要由随机过程主导,漂移是主要因素。鞭毛藻和硅藻的同时出现显示出季节性模式,在秋季观察到的相互作用最高。此外,Syndiniales与鞭毛藻和硅藻的相互作用强调了寄生虫在富营养化条件下的作用。黄杆菌科和红杆菌科是最常与鞭毛藻和硅藻相互作用的细菌类群,鞭毛藻和细菌之间的相互作用比硅藻和细菌之间的相互作用更复杂。总的来说,这项研究提供了加深我们对沿海富营养化水域浮游植物动态的理解的结果。重要的鞭毛藻和硅藻是沿海水域的主要浮游植物。公海中鞭毛藻和硅藻的组成和多样性已得到充分记录;然而,他们对长期富营养化条件的适应在多大程度上影响他们对环境干扰的反应仍然不确定。这里,我们全年调查了富营养化海湾中鞭毛藻和硅藻的相互作用和组装过程。我们的发现表明,鞭毛藻和硅藻之间的相互作用主要是由季节变化形成的,而长期的富营养化条件往往会放大社区聚集中的随机过程。这些发现为长期富营养化对富营养化水域浮游植物动态的影响提供了新的视角。
Dinoflagellates and diatoms are highly prevalent and ecologically important phytoplankton in coastal waters, greatly contributing to primary productivity in marine ecosystems. Although their composition and diversity have been extensively elucidated in the open ocean, their interaction patterns and community assembly in long-term eutrophic coastal waters remain poorly understood. This investigation aimed to elucidate the seasonal successional patterns of
dinoflagellates and diatoms by 18S rRNA gene amplicon sequencing in a semi-enclosed bay. The results revealed that dinoflagellate and diatom communities have pronounced seasonal succession patterns, which are primarily associated with temperature. Furthermore, the most prevalent species throughout the year were Heterocapsa rotundata and Skeletonema costatum. Moreover, the assembly of dinoflagellate and diatom communities was mainly dominated by stochastic processes, with drift being the major factor. The co-occurrence of
dinoflagellates and diatoms showed seasonal patterns, with the highest interactions observed in autumn. In addition, interactions of Syndiniales with dinoflagellates and diatoms highlighted the roles of parasites in eutrophic conditions. Flavobacteriaceae and Rhodobacteraceae are the bacterial taxa that most frequently interacted with dinoflagellates and diatoms, with interactions between
dinoflagellates and bacteria being more complex than those between diatoms and bacteria. Overall, this study provides results that deepen our understanding of the phytoplankton dynamics in coastal eutrophic waters.IMPORTANCEDinoflagellates and diatoms are major phytoplankton groups in coastal waters. The composition and diversity of
dinoflagellates and diatoms in the open ocean have been well documented; however, it remains uncertain to what extent their adaptation to long-term eutrophic conditions influences their response to environmental disturbances. Here, we investigated the interactions and assembly processes of dinoflagellates and diatoms in a eutrophic bay throughout the whole year. Our findings revealed that interactions between dinoflagellates and diatoms are primarily shaped by seasonal transitions, while prolonged eutrophic conditions tend to amplify stochastic processes in community assembly. These findings provide novel perspectives on the influence of long-term eutrophication on phytoplankton dynamics within eutrophic waters.